CN206164354U - Power lightning protection circuit and power adapter - Google Patents

Abstract

The utility model relates to a power lightning protection circuit and adopt power adapter of this power lightning protection circuit, wherein this power lightning protection circuit includes live wire end, zero line end, fuse F1, fuse F2, common mode inductance LF1, common mode inductance LF2, piezo-resistor MOV1, thermistor NTC1 and rectifier bridge BD1, common mode inductance LF1 includes first coil and second coil, common mode inductance LF2 includes third coil and fourth coil; a first input end of the rectifier bridge BD1 is connected with a live wire end sequentially through a third coil, a thermistor NTC1, a fuse F2, a first coil and a fuse F1; a second input end of the rectifier bridge BD1 is connected with the zero line end through the fourth coil and the second coil in sequence; one end of the varistor MOV1 is connected to the connection node of the first coil and the fuse F2, and the other end of the varistor MOV1 is connected to the connection node of the second coil and the fourth coil. Above-mentioned power lightning protection circuit and power adapter can not only improve the anti lightning stroke ability and the anti-surge effect of power, can also strengthen electrical safety.

Description

Power lightning protection circuit and power adapter

technical field

The utility model relates to the field of electronic technology, in particular to a power supply lightning protection circuit and a power adapter.

Background technique

With the development of electronic technology, communication equipment, household appliances and other electronic equipment are becoming more and more sophisticated, and their requirements for the working environment are also getting higher and higher, and the instantaneous overvoltage of lightning and surge will cause large energy to electronic equipment through the line. The impact may cause damage to components or equipment in light cases, or may cause chain accidents in severe cases, such as breakdown of equipment insulation protection, resulting in personal injury accidents, etc.

In order to improve the electrical safety of electronic equipment, many electronic equipment are currently designed for lightning protection. In the prior art, a piezoresistor is usually connected between the live wire and the neutral wire, and the high energy brought by lightning is absorbed through the piezoresistor. Although this method has a simple circuit and is easy to implement, its energy absorption effect is limited. When lightning strikes and surge strikes come, it will leave a relatively high "residual voltage", which is still a great threat to the subsequent equipment.

Utility model content

Based on this, it is necessary to provide a power supply lightning protection circuit and a power adapter, which can improve the anti-lightning ability and anti-surge effect of the power supply, and can also enhance electrical safety.

The utility model discloses a lightning protection circuit for a power supply, which comprises a live line terminal, a neutral line terminal, a fuse F1, a fuse F2, a common mode inductor LF1, a common mode inductor LF2, a piezoresistor MOV1, a thermistor NTC1 and a rectifier bridge BD1 ,in:

The common mode inductor LF1 includes a first coil and a second coil, and the common mode inductor LF2 includes a third coil and a fourth coil;

The first input terminal of the rectifier bridge BD1 is sequentially connected to the live wire end through the third coil, the thermistor NTC1, the fuse F2, the first coil and the fuse F1;

The second input terminal of the rectifier bridge BD1 is sequentially connected to the neutral terminal through the fourth coil and the second coil;

One end of the varistor MOV1 is connected to the connection node of the first coil and the fuse F2, and the other end of the varistor MOV1 is connected to the connection node of the second coil and the fourth coil.

As an implementation manner, the power supply lightning protection circuit further includes an electrolytic capacitor EC1, the two ends of the electrolytic capacitor EC1 are respectively connected to the first output terminal and the second output terminal of the rectifier bridge BD1, and the rectifier bridge BD1 The second output terminal is grounded.

As an implementation manner, the power supply lightning protection circuit further includes a differential mode capacitor CX1, one end of the differential mode capacitor CX1 is connected to the connection node of the thermistor NTC1 and the third coil, and the differential mode capacitor CX1 The other end of is connected to the connection node of the second coil and the fourth coil.

As an implementation, the power supply lightning protection circuit further includes a piezoresistor string connected in parallel with the piezoresistor MOV1, and the piezoresistor string includes a piezoresistor MOV2 and a piezoresistor MOV3 .

As an implementation manner, the power supply lightning protection circuit further includes a gas discharge tube GDT1, and a connection node of the piezoresistor MOV2 and the piezoresistor MOV3 is grounded through the gas discharge tube GDT1.

As an implementation, the power supply lightning protection circuit further includes a transient voltage suppression diode TVS1, one end of the transient voltage suppression diode TVS1 is connected to the first output end of the rectifier bridge BD1, and the transient voltage suppression diode The other end of TVS1 is grounded.

As an implementation, the power supply lightning protection circuit further includes a transient voltage suppression diode TVS2 and a transient voltage suppression diode TVS3, and the first output terminal of the rectifier bridge BD1 passes through the transient voltage suppression diode TVS2 and the transient voltage suppression diode TVS3 in sequence. The transient voltage suppression diode TVS3 is grounded.

The utility model also discloses a power adapter, which includes the power lightning protection circuit described in any one of the above-mentioned implementation modes.

As an implementation manner, the power adapter further includes a voltage conversion circuit, the first input terminal and the second input terminal of the voltage conversion circuit are connected to the first output terminal and the second output terminal of the rectifier bridge BD1 respectively.

As an implementation manner, the power adapter further includes a filter circuit, the input end of the filter circuit is connected to the output end of the rectifier bridge BD1, and the output end of the filter circuit is connected to the input end of the voltage conversion circuit.

The lightning protection circuit for the power supply and the power adapter above adopt double insurance, double common mode, high-energy pressure-sensitive components and surge suppression components to double absorb lightning strike energy and surge energy, and provide double protection for the subsequent circuit, which not only improves the anti- Lightning strike capability and anti-surge effect also enhance electrical safety.

Description of drawings

Fig. 1 is the circuit diagram of the lightning protection circuit of the power supply of an embodiment of the utility model;

Fig. 2 is the circuit diagram of the lightning protection circuit of the power supply of another embodiment of the utility model;

Fig. 3 is a circuit diagram of a power supply lightning protection circuit according to another embodiment of the present invention;

Fig. 4 is a schematic structural diagram of a power adapter according to an embodiment of the present invention;

FIG. 5 is a schematic structural diagram of a power adapter according to another embodiment of the present invention.

detailed description

In order to make the above purpose, features and advantages of the present utility model more obvious and understandable, the specific implementation of the present utility model will be described in detail below in conjunction with the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a full understanding of the present invention. However, the utility model can be implemented in many other ways different from those described here, and those skilled in the art can make similar improvements without violating the connotation of the utility model, so the utility model is not limited by the specific embodiments disclosed below limit.

Please refer to Fig. 1, as shown in Fig. 1, the high-voltage switch characteristic instrument 100 of an embodiment includes fuse F1, fuse F2, common-mode inductance LF1, common-mode inductance LF2, varistor MOV1, thermistor NTC1 and rectifier bridge BD1, wherein, the common mode inductor LF1 includes the first coil and the second coil, and the common mode inductor LF2 includes the third coil and the fourth coil; the first input end of the rectifier bridge BD1 passes through the third coil, thermistor NTC1, fuse F2, the first coil and the fuse F1 are connected to the live wire end; the second input end of the rectifier bridge BD1 is connected to the neutral wire end through the fourth coil and the second coil in turn; one end of the varistor MOV1 is connected to the connection node of the first coil and the fuse F2 , the other end of the varistor MOV1 is connected to the connection node of the second coil and the fourth coil.

In this embodiment, the common mode inductor LF1 and the piezoresistor MOV1 form the primary surge absorbing circuit. When the lightning strike voltage or large surge voltage is applied to both ends of the live line and the neutral line, the fuse F1, the common mode inductor LF1 and the The varistor MOV1 absorbs high energy from lightning strikes or surges. The thermistor NTC1 and the common mode inductor LF2 form a secondary surge absorbing circuit, which consumes the residual energy not absorbed by the primary surge absorbing circuit through damping, and further weakens the energy impact caused by lightning strikes or surges. Through the multi-stage surge absorbing circuit, it can effectively reduce the lightning residual voltage and surge residual voltage, and the anti-lightning effect is better.

In order to enhance the surge absorption effect, for example, the varistor MOV1 adopts a metal oxide varistor, such as a zinc oxide varistor. For example, the thermistor NTC1 uses a negative temperature coefficient thermistor. For example, the inductance of the common mode inductor LF1 is smaller than the inductance of the common mode inductor LF2. For another example, the common mode inductor LF1 adopts a small common mode inductor, and the common mode inductor LF2 adopts a large common mode inductor. For another example, the inductance of the common mode inductor LF1 is less than 30mH, and the inductance of the common mode inductor LF2 is greater than 50mH.

In this embodiment, the fuse F1 acts as a primary protection. When the lightning strike voltage or large surge voltage applied to both ends of the live line and the neutral line is too large, for example, the lightning strike energy or surge energy is greater than the maximum that the lightning protection circuit of the power supply can absorb. When the energy is high, the current on the live line will be greater than the fusing current of the fuse F1, which will cause the fuse F1 to blow, and cut off the connection between the subsequent circuit or equipment and the power supply, so as to avoid the subsequent circuit or equipment from continuing to work under the impact of large energy. fire accident. Fuse F2 acts as a protection for the subsequent stage. If the residual energy after passing through the common mode inductor LF1 and varistor MOV1 is too large, causing the current flowing through the fuse F2 to be greater than its fusing current, the fuse F2 will blow and cut off the subsequent circuit or equipment. The connection between the power sources to avoid fire accidents caused by the subsequent circuit or equipment continuing to work under the impact of large energy. In this way, the fuse F1 and the fuse F2 form a double protection, even if the energy of the lightning strike or the large surge energy is too large and cannot be completed completely, it can also protect the safety of the subsequent circuit or equipment.

Wherein, the fusing current of the fuse F1 is greater than the fusing current of the fuse F2, for example, the fuse F1 is a fuse with a specification of 6.3A, and the fuse F2 is a fuse with a specification of 3A.

In this embodiment, the live wire end is used to connect the live wire in the power line, and the neutral wire end is used to connect the neutral wire in the power line. direct current.

It should be understood that between the common-mode inductor LF2 and the rectifier bridge BD1, corresponding functional circuits, such as electromagnetic interference suppression circuits, filter circuits, and voltage conversion circuits, may also be provided according to actual needs.

The above power supply lightning protection circuit adopts double insurance, double common mode, high-energy pressure-sensitive components and surge suppression components to double absorb lightning energy and surge energy, and perform double protection on the subsequent circuit, which not only improves the ability to resist lightning strikes and Anti-surge effect, and enhance electrical safety.

In one embodiment, the power supply lightning protection circuit further includes at least one of electrolytic capacitor EC1 and differential mode capacitor CX1. As shown in FIG. 2 , both ends of the electrolytic capacitor EC1 are respectively connected to the first output terminal and the second output terminal of the rectifier bridge BD1 , and the second output terminal of the rectifier bridge BD1 is grounded. One end of the differential mode capacitor CX1 is connected to the connection node of the fuse F2 and the third coil, and the other end of the differential mode capacitor CX1 is connected to the connection node of the second coil and the fourth coil.

Among them, the electrolytic capacitor EC1 acts as a filter to filter out some interference signals in the circuit; the differential mode capacitor CX1 is used to filter out the differential mode interference signals in the circuit. Electromagnetic compatibility of the lightning protection circuit for the power supply can be improved by using the electrolytic capacitor EC1 and/or the differential mode capacitor CX1.

In one embodiment, the lightning protection circuit for the power supply further includes a piezoresistor string connected in parallel with the piezoresistor MOV1. For example, as shown in FIG. 3 , the varistor string includes a varistor MOV2 and a varistor MOV3 connected in series. As another example, one end of the varistor MOV2 is connected to the connection node between the first coil and the fuse F2, the other end of the varistor MOV2 is connected to one end of the varistor MOV3, and the other end of the varistor MOV3 is connected to the second coil and the fourth coil. Connection nodes for coils.

In one embodiment, the lightning protection circuit for the power supply further includes a gas discharge tube GDT1, for example, the gas discharge tube GDT1 is a ceramic gas discharge tube. The connection node of the varistor MOV2 and the varistor MOV3 is grounded through the gas discharge tube GDT1. When the voltage difference applied to both ends of the gas discharge tube GDT1 exceeds the insulation strength of the gas in the gas discharge tube, the gas gap between the two electrodes will break down the discharge, and the gas discharge tube GDT1 will change from the original insulating state to the conductive state. The lightning surge current is introduced into the earth through the gas discharge tube GDT1 to form a discharge circuit. After conduction, the voltage between the two poles of the gas discharge tube GDT1 is maintained at the residual voltage level determined by the discharge arc.

In one embodiment, the power supply lightning protection circuit further includes a transient voltage suppression diode TVS1, one end of the transient voltage suppression diode TVS1 is connected to the first output end of the rectifier bridge BD1, and the other end of the transient voltage suppression diode TVS1 is grounded. For example, if TVS1 uses a unidirectional transient voltage suppressor diode, the cathode of the transient voltage suppressor diode TVS1 is connected to the first output terminal of the rectifier bridge BD1, and the anode of the transient voltage suppressor diode TVS1 is grounded. When the positive and negative poles of the transient voltage suppression diode TVS1 are subjected to a reverse transient high-energy impact, it will be broken down, and the high impedance between the positive and negative poles will quickly become low impedance, absorbing up to several thousand watts of surge power , so that the voltage between the positive and negative poles is clamped at a predetermined value. If TVS1 adopts a bidirectional transient voltage suppressor diode, there is no distinction between positive and negative poles, any one end of which is connected to the first output end of the rectifier bridge BD1, and the other end is grounded.

In one embodiment, in order to further strengthen the voltage stabilizing capability, the lightning protection circuit of the power supply further includes a transient voltage suppression diode TVS2 and a transient voltage suppression diode TVS3, wherein the first output terminal of the rectifier bridge BD1 passes through the transient voltage suppression diode TVS2 sequentially. And the transient voltage suppression diode TVS3 is grounded.

The utility model also discloses a power adapter, as shown in Figure 4, the power adapter 400 includes a power supply lightning protection circuit 410, wherein the specific implementation of the power supply lightning protection circuit 410 is the power supply lightning protection circuit described in any of the above-mentioned embodiments As shown, for example, it can be implemented by using the power supply lightning protection circuit of any one of the above-mentioned embodiments.

As an implementation, as shown in FIG. 5 , the power adapter 400 further includes at least one of a voltage conversion circuit 430 and a filter circuit 450, wherein the input terminal 430 of the voltage conversion circuit is connected to the output terminal of the power supply lightning protection circuit 410, for example The first input terminal and the second input terminal of the voltage conversion circuit 430 are connected to the first output terminal and the second output terminal of the rectifier bridge BD1 respectively. The filter circuit 450 is respectively connected to the power supply lightning protection circuit and the voltage conversion circuit. For example, the input terminal of the filter circuit is connected to the output terminal of the power supply lightning protection circuit 410, and the output terminal of the filter circuit is connected to the input terminal of the voltage conversion circuit. For example, the filter circuit includes two input terminals, respectively connected to the first output terminal and the second output terminal of the rectifier bridge BD1.

In this embodiment, the voltage conversion circuit is used to convert the mains power into the working voltage required by the electronic equipment. For example, a corresponding voltage conversion circuit is used to convert 220V alternating current into various voltages such as 5V, 10V and/or 12V according to the power consumption requirements of different electronic devices. The filter circuit is used to filter out the interference signal in the circuit, the electrical signal output from the rectifier bridge BD1 is filtered by the filter circuit, and then input to the voltage conversion circuit for voltage conversion.

The above-mentioned power adapter adopts the above-mentioned power supply lightning protection circuit, through double insurance, double common mode, high-energy pressure-sensitive components and surge suppression components, double absorbs lightning strike energy and surge energy, and double protects the subsequent circuit. Therefore, it not only improves the anti-lightning ability and anti-surge effect, but also enhances electrical safety.

It should be noted that, in the above-mentioned embodiments, when an element is considered to be “connected” to another element, it may be directly connected to another element or there may be an intermediate element at the same time. In contrast, when an element is referred to as being "directly" connected to another element, there are no intervening elements present.

The technical features of the above-mentioned embodiments can be combined arbitrarily. To make the description concise, all possible combinations of the technical features in the above-mentioned embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, should be considered as within the scope of this specification.

The above-mentioned embodiments only express several implementation modes of the utility model, and the description thereof is relatively specific and detailed, but it should not be interpreted as a limitation on the patent scope of the utility model. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the utility model, and these all belong to the protection scope of the utility model. Therefore, the scope of protection of the utility model patent should be based on the appended claims.

Claims (10)

1. a kind of power lightning protection circuit, it is characterised in that including zero line, zero line side, electric fuse F1, electric fuse F2, common mode electricity Sense LF1, common mode inductance LF2, varistor MOV1, critesistor NTC1 and rectifier bridge BD1, wherein：

The common mode inductance LF1 includes first coil and the second coil, and the common mode inductance LF2 includes tertiary coil and the 4th line Circle；

The first input end of the rectifier bridge BD1 passes sequentially through the tertiary coil, the critesistor NTC1, the electric fuse F2, the first coil and the electric fuse F1 connect the zero line；

Second input of the rectifier bridge BD1 passes sequentially through the 4th coil and second coil connects the zero line End；

One end of the varistor MOV1 connects the connecting node of the first coil and the electric fuse F2, the pressure-sensitive electricity The other end of resistance MOV1 connects the connecting node of second coil and the 4th coil.

2. power lightning protection circuit as claimed in claim 1, it is characterised in that the power lightning protection circuit also includes electrochemical capacitor The two ends of EC1, the electrochemical capacitor EC1 connect respectively first outfan and the second outfan of the rectifier bridge BD1, described whole Second output head grounding of stream bridge BD1.

3. power lightning protection circuit as claimed in claim 1, it is characterised in that the power lightning protection circuit also includes differential mode capacitor One end of CX1, the differential mode capacitor CX1 connects the connecting node of the critesistor NTC1 and the tertiary coil, the difference The other end of mould electric capacity CX1 connects the connecting node of second coil and the 4th coil.

4. power lightning protection circuit as claimed in claim 1, it is characterised in that the power lightning protection circuit also includes varistor String, the varistor string is in parallel with the varistor MOV1, and the varistor string includes the varistor MOV2 of series connection With varistor MOV3.

5. power lightning protection circuit as claimed in claim 4, it is characterised in that the power lightning protection circuit also includes gas-discharge tube The connecting node of GDT1, the varistor MOV2 and the varistor MOV3 is grounded by the gas-discharge tube GDT1.

6. power lightning protection circuit as claimed in claim 1, it is characterised in that the power lightning protection circuit also presses down including transient voltage One end of diode TVS1 processed, the transient voltage suppressor diode TVS1 connects first outfan of the rectifier bridge BD1, institute State the other end ground connection of transient voltage suppressor diode TVS1.

7. power lightning protection circuit as claimed in claim 6, it is characterised in that the power lightning protection circuit also presses down including transient voltage Diode TVS2 processed and transient voltage suppressor diode TVS3, first outfan of the rectifier bridge BD1 passes sequentially through the wink The state voltage suppression diode TVS2 and transient voltage suppressor diode TVS3 is grounded.

8. a kind of power supply adaptor, it is characterised in that include the power lightning protection circuit as any one of claim 1 to 7.

9. power supply adaptor as claimed in claim 8, it is characterised in that the power supply adaptor also includes voltage conversion circuit, The first input end of the voltage conversion circuit and the second input connect respectively first outfan of the rectifier bridge BD1 and Two outfans.

10. power supply adaptor as claimed in claim 9, it is characterised in that the power supply adaptor also includes filter circuit, described The input of filter circuit connects the outfan of the rectifier bridge BD1, and the outfan of the filter circuit connects the voltage and turns Change the input of circuit.